Cleaning the Plastic Center Console

This may concern the normal Prius as well as the Prime (don't know) but was wondering if anyone can recommend a good cleaning solution for the plastic center console (in front of the cupholders).

My console is white... and all of a sudden I noticed a circular black mark on the square section where you can put things (my Plus trim doesn't have the wireless phone-recharging function, it's just plain white there). The black mark didn't look like a scratch, and almost appeared to be "under" the sealant coat. But it wasn't there when I bought it, making that unlikely. Still, I tried using a soft cloth and water... and scrubbing as hard as I could (gently) saw no change in it at all. So, I took it into the dealer today just on a whim. They were nice enough to drive it back to detailing, and a few minutes later, it was gone. The service tech simply said detailing used a solution to get it (whatever it was) off.

What's strange is that I pretty much never put anything in that square space. I must have put something there just for a second temporarily somehow... but if anyone has any suggestions on a safe product to buy that won't take off the sealant, but will still clean, where water and soft cloth does absolutely nothing, please let us know so the next time this happens I can just do it myself. I suppose should've asked at the dealership, but you don't actually speak to the detailing people directly...